How To Fix M8644 - Field & is not defined as a search field in this line layout

SAP Error Message - Details

• Message type: E = Error

• Message class: M8 - Invoice Verification/Valuation

• Message number: 644

• Message text: Field & is not defined as a search field in this line layout

What causes this issue?

The cursor is on a field which is not a search field in the current
line structure.

How to fix this error?

If you position the cursor on the command line and select F5, a window
appears which contains the fields which you can search for in the
current line structure.
You can only search for the content of other fields in the following
way:
select a line structure in which the field is defined as a search field.
your system administrator can define the field as a search field in the
current line structure in invoice verification via customizing.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message M8644 - Field & is not defined as a search field in this line layout ?

  The SAP error message M8644, which states "Field & is not defined as a search field in this line layout," typically occurs in the context of SAP's Material Management (MM) module, particularly when working with line layouts in transaction codes like ME21N (Create Purchase Order) or ME22N (Change Purchase Order).
  
  Cause:
  This error arises when you attempt to use a field in a search or filter operation that has not been defined as a search field in the current line layout configuration. This can happen due to:
  
  Customizations: If the line layout has been customized and the field in question was not included in the layout.
  Field Configuration: The field may not be set up correctly in the system to be used as a search field.
  User Authorizations: The user may not have the necessary authorizations to access certain fields.
  
  
  Solution:
  To resolve the M8644 error, you can take the following steps:
  
  
  Check Line Layout Configuration:
  
  Go to the